The Argus II

By: Ahmaad Randall

What is it?

The world’s first approved device intended to restore some functional vision

for people suffering from blindness.

What is it actually?

1.)

2.)

3.)

1.) Epiretinal prosthesis

2.) Video Processing Unit and cable (VPU)

3.) Glasses

The Argus II is made up of three different parts:

The Epiretinal Prosthesis

Main part of The Argus II

Needs surgery to be implanted

Made up of three different parts:

1.) An Electronics Case

2.) An Electrode Ray

3.) Receiving Coil

Surgery

Completed within four hours

Requires general anesthesia

Only one night hospital stay

Who is it for?

Patients with severe retinitis pigmentosa

Adults 25 years or older

Bare or no light perception

A previous history of useful form vision

How does it work?

1.) Surgically implanted in one eye. The individual wears glasses equipped with a camera that captures images and converts them into a series of small electrical pulses

2.) The pulses are transmitted wirelessly to the prosthesis and its array of electrodes on the surface of the retina

3.) These pulses are intended to stimulate the retina’s remaining cells, resulting in the corresponding perception of patterns of light in the brain

4.) Then the patient then learns to interpret these visual patterns, thereby regaining some visual function

For Better Understanding…

After Surgery

Normally wait three to four months to turn the actual device on

Once turned on, it is highly advised you seek and attend a physical therapist who can help you learn how to use the Argus II

Physical Therapist will also show you how to interpret what you are seeing

Results

Visual Acuity of 20/1260

-blindness is 20/500 (WHO) & 20/200 in the US

Implanted in over 80 people to date

Longest user is approaching seven years

Best visual acuity of 20/1000

Improvements in Vision

Most participants were able to perform basic activities better with the retinal prosthesis than without it

Many were able to locate lights and windows, follow lines in a crosswalk, or avoid running into things as they walked

Some could sort laundry or determine where other people were located in a room

About half of the subjects were able to read very large letters (about 9 inches high).

Quick Review

Normal eye test

Standard test for people who are legally blind (20/200)

Chart is one meter long

Highest reading is 20/1000

(First line)

Visual Results

Expenses

The device cost 150,000

Hospital stay

Physical Therapy for 5-6 months after your surgery every week 2-3 times a week

Limitations

The cost

Imaging is good; but can still improve greatly

Availability

Future

Better imaging, hopefully 20/400!

Cheaper

Less PT

Faster Recovery

Works Cited

Mann, Alfred. "Second Sight." Second Sight. Second Sight Medical Products, 2014. Web. 06 Oct. 2014.

"U.S. Food and Drug Administration." Argus II Retinal Prosthesis System. Ed. U.S. Department of Health and Human Services.

FDA.gov, 17 June 2014. Web. 06 Oct. 2014.

"Argus Retinal Prosthesis." Wikipedia. Ed. Wikipedia. Wikimedia Foundation, 25 Sept. 2014. Web. 06 Oct. 2014.

Nisbet, Betsy. "U-M Kellogg Eye Center Performs First Two Retinal Prosthesis Implants in U.S. since FDA Approval." U-M Kellogg Eye Center Performs First Two Retinal Prosthesis Implants in U.S. since FDA Approval. Kellog Eye Center, 23 Jan. 2013. Web. 06 Oct. 2014.

Barret, John. "University Libraries." Optogenetic Approaches to Retinal Prosthesis (2014): n. pag. PubMed. Web. 6 Oct. 2014. <Optogenetic approaches to retinal prosthesis>.